Perchlorate, thiocyanate and nitrate are sodium/iodide symporter (NIS) inhibitors that block iodi... more Perchlorate, thiocyanate and nitrate are sodium/iodide symporter (NIS) inhibitors that block iodide uptake into the thyroid, thus affecting thyroid function. Thyroid dysfunction can adversely affect somatic growth and development in children. To our knowledge, no studies have examined effects of NIS inhibitors on body size measures. We investigated associations between NIS inhibitors and childhood growth in 940 girls from the Puberty Study of the Breast Cancer and Environment Research Program. Urine samples collected from girls 6-8 years of age at enrollment (2004-2007) from New York City, greater Cincinnati, Ohio and the Bay Area in California were analyzed for NIS inhibitors and creatinine (C). The longitudinal association between NIS inhibitors and anthropometric measures (height, waist circumference and body mass index (BMI)) during at least 3 visits was examined using mixed effects linear models, adjusted for race and site. Compared to girls in the low exposure group (3.6, 626 µg/gC and 500 mg/gC, median, perchlorate, thiocyanate and nitrate, respectively) girls with the highest NIS inhibitor exposure (9.6, 2343 µg/gC and 955 mg/gC, median perchlorate, thiocyanate and nitrate, respectively) had slower growth in waist circumference and BMI but not height. Significant differences in the predicted mean waist circumference and BMI between the low and high exposure groups were observed beginning at 11 years of age. Higher NIS inhibitor exposure biomarkers were associated with reductions in waist circumference and BMI. These findings underscore the need to assess exposure to NIS inhibitors with respect to their influence on childhood growth.
Exposures of children to phthalates, parabens, and bisphenol-A (BPA) are of concern because of th... more Exposures of children to phthalates, parabens, and bisphenol-A (BPA) are of concern because of their hormonal potential. These agents are found in a wide range of foods and packaging. We investigated whether intake of certain foods predict exposures to these chemicals in young girls. Among 1101 girls (6-8 years at enrollment) from the Breast Cancer and Environment Research Program (BCERP) study, we measured urinary exposure biomarkers for phthalates, parabens, and BPA and assessed dietary intake using 24-h recall 2-4 times. We examined the average daily servings of major and minor food groups categorized as 0 to <0.5, 0.5 to <1 and ≥ 1 servings per day. Items included dairy, eggs, fats, fish, fruit, single grains, meat, non-poultry meats, pasta, poultry and vegetables. Covariate-adjusted least squares geometric means and 95% confidence intervals of creatinine-corrected phthalate and phenol metabolite concentrations in urine were calculated in relation to food intake. Grains, f...
Lignans and flavonols are dietary phytoestrogens found at high concentrations in the Western Diet... more Lignans and flavonols are dietary phytoestrogens found at high concentrations in the Western Diet. They have potential to influence the timing of puberty. We hypothesized that greater consumption of these 2 phytoestrogens would be related to later age at pubertal onset among girls. Pubertal assessment and 24-hour diet recall data were available for 1178 girls, ages 6 to 8 years (mean 7.3 years) in the Breast Cancer and Environment Research Project Puberty Study. Lignan and flavonol intakes were mainly derived from fruit and vegetable consumption. Average consumption was 6.5 mg/d for flavonols and 0.6 mg/d for lignans. Highest flavonol consumption (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5 mg/d) was associated with later breast development (adjusted hazards ratio [HR]: 0.74, 95% CI: [0.61-0.91]) compared to 2 to 5 mg/d (adjusted HR: 0.84, 95% CI: [0.70-1.0]) and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;2 mg/d (referent group; P-trend = .006). Flavonol intake was not associated with pubic hair development. Lignan intake was not associated with either breast or pubic hair development. Dietary intake was only weakly correlated with urinary enterolactone, a biomarker for lignans (RS = 0.13). Consistent with biologic properties of phytoestrogens that indicate hormonal activity, their consumption may be associated with reproductive end points, even in childhood.
Journal of Exposure Science and Environmental Epidemiology, 2012
Perchlorate, nitrate and thiocyanate are ubiquitous in the environment, and human exposure to the... more Perchlorate, nitrate and thiocyanate are ubiquitous in the environment, and human exposure to these chemicals is accurately measured in urine. Biomarkers of these chemicals represent a person's recent exposure, however, little is known on the temporal variability of the use of a single measurement of these biomarkers. Healthy Hispanic and Black children (6-10-year-old) donated urine samples over 6 months. To assess temporal variability, we used three statistical methods (n = 29; 153 urine samples): intraclass correlation coefficient (ICC), Spearman's correlation coefficient between concentrations measured at different timepoints and surrogate category analysis to assess how well tertile ranking by a single biomarker measurement represented the average concentration over 6 months. The ICC measure of reproducibility was poor (0.10-0.12) for perchlorate, nitrate and iodide; and fair for thiocyanate (0.36). The correlations for each biomarker across multiple sampling times ranged from 0.01-0.57. Surrogate analysis showed consistent results for almost every surrogate tertile. Results demonstrate fair temporal reliability in the spot urine concentrations of the three NIS inhibitors and iodide. Surrogate analysis show that single-spot urine samples reliably categorize participant's exposure providing support for the use of a single sample as an exposure measure in epidemiological studies that use relative ranking of exposure.
Methods-Urinary concentrations of nine phthalate metabolites: monoethyl (MEP); mono-nbutyl (MBP);... more Methods-Urinary concentrations of nine phthalate metabolites: monoethyl (MEP); mono-nbutyl (MBP); mono-(3-carboxypropyl) (MCPP); monobenzyl (MBzP); mono-isobutyl (MiBP); mono-(2-ethylhexyl) (MEHP); mono-(2-ethyl-5-oxohexyl) (MEOHP); mono-(2-ethyl-5carboxypentyl) (MECPP); and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and the molar sum of the low molecular-weight phthalate metabolites (low MWP: MEP, MBP and MiBP) and high molecular-weight phthalate metabolites (high MWP: MECPP, MEHHP, MEOHP, MEHP and MBzP) and of four di-(2-ethylhexyl) phthalate (DEHP) metabolites (ΣDEHP: MEHP, MEHHP, MEOHP, MECPP) and anthropometry, including body mass index and waist circumference were measured among 387 Hispanic and Black, New York City children who were between six and eight years at cohort enrollment (2004)(2005)(2006)(2007). Relationships between baseline metabolite concentrations and body size characteristics obtained one year later were examined using multivariate-adjusted geometric means for each body size characteristic by continuous and categories of phthalate metabolite concentrations. Stratified analyses by body size (age/sex specific) were conducted.
There is widespread concern regarding the safety of silver-mercury amalgam dental restorations, y... more There is widespread concern regarding the safety of silver-mercury amalgam dental restorations, yet little evidence to support their harm or safety. We examined whether mercury dental amalgams are adversely associated with cognitive functioning in a cross-sectional sample of healthy working adults. We studied 550 adults, 30-49 years of age, who were not occupationally exposed to mercury. Participants were representative of employees at a major urban medical center. Each participant underwent a neuropsychologic test battery, a structured questionnaire, a modified dental examination, and collection of blood and urine samples. Mercury exposure was assessed using a) urinary mercury concentration (UHg); b) the total number of amalgam surfaces; and c) the number of occlusal amalgam surfaces. Linear regression analysis was used to estimate associations between each marker of mercury exposure and each neuropsychologic test, adjusting for potential confounding variables. Exposure levels were relatively low. The mean UHg was 1.7 µg/g creatinine (range, 0.09-17.8); the mean total number of amalgam surfaces was 10.6 (range, 0-46) and the mean number of occlusal amalgam surfaces was 6.1 (range, 0-19). No measure of exposure was significantly associated with the scores on any neuropsychologic test in analyses that adjusted for the sampling design and other covariates. In a sample of healthy working adults, mercury exposure derived from dental amalgam restorations was not associated with any detectable deficits in cognitive or fine motor functioning.
To examine racial/ethnic differences in diet and physical activity behaviors in ethnic minority N... more To examine racial/ethnic differences in diet and physical activity behaviors in ethnic minority New York City children. Cross-sectional data from a community-based study of 486 6- to 8-year-old children were used. Race/ethnicity was derived using a caregiver&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s report of child&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s race and Hispanic ancestry. Dietary intake was obtained by 24-hour diet recalls using the Nutrition Data System for Research. Physical activity was assessed with pedometers and caregiver interviews. We compared diet and activity measures across racial/ethnic subgroups using chi-square and analysis of variance tests. Multivariate analyses adjusted for age, gender, body mass index, and caregiver education (with breastfeeding history and total energy intake included in diet models). Participants (N = 486) were categorized as Mexican (29.4%), Dominican (8.4%), Puerto Rican (20.6%), other/mixed Hispanic (14.0%), or non-Hispanic black (27.6%). Obesity rates were lower in non-Hispanic blacks (18%) than in Hispanics (31%). Mexicans had the lowest obesity rates among Hispanic subgroups (25%), and Dominicans had the highest (39%). There were differences in mean daily servings of food groups, with Mexicans having healthier diets and Puerto Ricans and non-Hispanic Blacks having less healthy diets. Sedentary time was lower in Mexicans than in other groups in adjusted models. Examination of additional models, including home language, did not show significant differences in the estimates. Diet and activity behaviors varied across racial/ethnic subgroups. Specifically, Mexican children had healthier diets, the least amount of sedentary time, and the lowest rates of obesity among the Hispanic subgroups examined. Targeted interventions in ethnic subgroups may be warranted to address specific behaviors.
Perchlorate, thiocyanate and nitrate are sodium/iodide symporter (NIS) inhibitors that block iodi... more Perchlorate, thiocyanate and nitrate are sodium/iodide symporter (NIS) inhibitors that block iodide uptake into the thyroid, thus affecting thyroid function. Thyroid dysfunction can adversely affect somatic growth and development in children. To our knowledge, no studies have examined effects of NIS inhibitors on body size measures. We investigated associations between NIS inhibitors and childhood growth in 940 girls from the Puberty Study of the Breast Cancer and Environment Research Program. Urine samples collected from girls 6-8 years of age at enrollment (2004-2007) from New York City, greater Cincinnati, Ohio and the Bay Area in California were analyzed for NIS inhibitors and creatinine (C). The longitudinal association between NIS inhibitors and anthropometric measures (height, waist circumference and body mass index (BMI)) during at least 3 visits was examined using mixed effects linear models, adjusted for race and site. Compared to girls in the low exposure group (3.6, 626 µg/gC and 500 mg/gC, median, perchlorate, thiocyanate and nitrate, respectively) girls with the highest NIS inhibitor exposure (9.6, 2343 µg/gC and 955 mg/gC, median perchlorate, thiocyanate and nitrate, respectively) had slower growth in waist circumference and BMI but not height. Significant differences in the predicted mean waist circumference and BMI between the low and high exposure groups were observed beginning at 11 years of age. Higher NIS inhibitor exposure biomarkers were associated with reductions in waist circumference and BMI. These findings underscore the need to assess exposure to NIS inhibitors with respect to their influence on childhood growth.
Exposures of children to phthalates, parabens, and bisphenol-A (BPA) are of concern because of th... more Exposures of children to phthalates, parabens, and bisphenol-A (BPA) are of concern because of their hormonal potential. These agents are found in a wide range of foods and packaging. We investigated whether intake of certain foods predict exposures to these chemicals in young girls. Among 1101 girls (6-8 years at enrollment) from the Breast Cancer and Environment Research Program (BCERP) study, we measured urinary exposure biomarkers for phthalates, parabens, and BPA and assessed dietary intake using 24-h recall 2-4 times. We examined the average daily servings of major and minor food groups categorized as 0 to <0.5, 0.5 to <1 and ≥ 1 servings per day. Items included dairy, eggs, fats, fish, fruit, single grains, meat, non-poultry meats, pasta, poultry and vegetables. Covariate-adjusted least squares geometric means and 95% confidence intervals of creatinine-corrected phthalate and phenol metabolite concentrations in urine were calculated in relation to food intake. Grains, f...
Lignans and flavonols are dietary phytoestrogens found at high concentrations in the Western Diet... more Lignans and flavonols are dietary phytoestrogens found at high concentrations in the Western Diet. They have potential to influence the timing of puberty. We hypothesized that greater consumption of these 2 phytoestrogens would be related to later age at pubertal onset among girls. Pubertal assessment and 24-hour diet recall data were available for 1178 girls, ages 6 to 8 years (mean 7.3 years) in the Breast Cancer and Environment Research Project Puberty Study. Lignan and flavonol intakes were mainly derived from fruit and vegetable consumption. Average consumption was 6.5 mg/d for flavonols and 0.6 mg/d for lignans. Highest flavonol consumption (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5 mg/d) was associated with later breast development (adjusted hazards ratio [HR]: 0.74, 95% CI: [0.61-0.91]) compared to 2 to 5 mg/d (adjusted HR: 0.84, 95% CI: [0.70-1.0]) and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;2 mg/d (referent group; P-trend = .006). Flavonol intake was not associated with pubic hair development. Lignan intake was not associated with either breast or pubic hair development. Dietary intake was only weakly correlated with urinary enterolactone, a biomarker for lignans (RS = 0.13). Consistent with biologic properties of phytoestrogens that indicate hormonal activity, their consumption may be associated with reproductive end points, even in childhood.
Journal of Exposure Science and Environmental Epidemiology, 2012
Perchlorate, nitrate and thiocyanate are ubiquitous in the environment, and human exposure to the... more Perchlorate, nitrate and thiocyanate are ubiquitous in the environment, and human exposure to these chemicals is accurately measured in urine. Biomarkers of these chemicals represent a person's recent exposure, however, little is known on the temporal variability of the use of a single measurement of these biomarkers. Healthy Hispanic and Black children (6-10-year-old) donated urine samples over 6 months. To assess temporal variability, we used three statistical methods (n = 29; 153 urine samples): intraclass correlation coefficient (ICC), Spearman's correlation coefficient between concentrations measured at different timepoints and surrogate category analysis to assess how well tertile ranking by a single biomarker measurement represented the average concentration over 6 months. The ICC measure of reproducibility was poor (0.10-0.12) for perchlorate, nitrate and iodide; and fair for thiocyanate (0.36). The correlations for each biomarker across multiple sampling times ranged from 0.01-0.57. Surrogate analysis showed consistent results for almost every surrogate tertile. Results demonstrate fair temporal reliability in the spot urine concentrations of the three NIS inhibitors and iodide. Surrogate analysis show that single-spot urine samples reliably categorize participant's exposure providing support for the use of a single sample as an exposure measure in epidemiological studies that use relative ranking of exposure.
Methods-Urinary concentrations of nine phthalate metabolites: monoethyl (MEP); mono-nbutyl (MBP);... more Methods-Urinary concentrations of nine phthalate metabolites: monoethyl (MEP); mono-nbutyl (MBP); mono-(3-carboxypropyl) (MCPP); monobenzyl (MBzP); mono-isobutyl (MiBP); mono-(2-ethylhexyl) (MEHP); mono-(2-ethyl-5-oxohexyl) (MEOHP); mono-(2-ethyl-5carboxypentyl) (MECPP); and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and the molar sum of the low molecular-weight phthalate metabolites (low MWP: MEP, MBP and MiBP) and high molecular-weight phthalate metabolites (high MWP: MECPP, MEHHP, MEOHP, MEHP and MBzP) and of four di-(2-ethylhexyl) phthalate (DEHP) metabolites (ΣDEHP: MEHP, MEHHP, MEOHP, MECPP) and anthropometry, including body mass index and waist circumference were measured among 387 Hispanic and Black, New York City children who were between six and eight years at cohort enrollment (2004)(2005)(2006)(2007). Relationships between baseline metabolite concentrations and body size characteristics obtained one year later were examined using multivariate-adjusted geometric means for each body size characteristic by continuous and categories of phthalate metabolite concentrations. Stratified analyses by body size (age/sex specific) were conducted.
There is widespread concern regarding the safety of silver-mercury amalgam dental restorations, y... more There is widespread concern regarding the safety of silver-mercury amalgam dental restorations, yet little evidence to support their harm or safety. We examined whether mercury dental amalgams are adversely associated with cognitive functioning in a cross-sectional sample of healthy working adults. We studied 550 adults, 30-49 years of age, who were not occupationally exposed to mercury. Participants were representative of employees at a major urban medical center. Each participant underwent a neuropsychologic test battery, a structured questionnaire, a modified dental examination, and collection of blood and urine samples. Mercury exposure was assessed using a) urinary mercury concentration (UHg); b) the total number of amalgam surfaces; and c) the number of occlusal amalgam surfaces. Linear regression analysis was used to estimate associations between each marker of mercury exposure and each neuropsychologic test, adjusting for potential confounding variables. Exposure levels were relatively low. The mean UHg was 1.7 µg/g creatinine (range, 0.09-17.8); the mean total number of amalgam surfaces was 10.6 (range, 0-46) and the mean number of occlusal amalgam surfaces was 6.1 (range, 0-19). No measure of exposure was significantly associated with the scores on any neuropsychologic test in analyses that adjusted for the sampling design and other covariates. In a sample of healthy working adults, mercury exposure derived from dental amalgam restorations was not associated with any detectable deficits in cognitive or fine motor functioning.
To examine racial/ethnic differences in diet and physical activity behaviors in ethnic minority N... more To examine racial/ethnic differences in diet and physical activity behaviors in ethnic minority New York City children. Cross-sectional data from a community-based study of 486 6- to 8-year-old children were used. Race/ethnicity was derived using a caregiver&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s report of child&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s race and Hispanic ancestry. Dietary intake was obtained by 24-hour diet recalls using the Nutrition Data System for Research. Physical activity was assessed with pedometers and caregiver interviews. We compared diet and activity measures across racial/ethnic subgroups using chi-square and analysis of variance tests. Multivariate analyses adjusted for age, gender, body mass index, and caregiver education (with breastfeeding history and total energy intake included in diet models). Participants (N = 486) were categorized as Mexican (29.4%), Dominican (8.4%), Puerto Rican (20.6%), other/mixed Hispanic (14.0%), or non-Hispanic black (27.6%). Obesity rates were lower in non-Hispanic blacks (18%) than in Hispanics (31%). Mexicans had the lowest obesity rates among Hispanic subgroups (25%), and Dominicans had the highest (39%). There were differences in mean daily servings of food groups, with Mexicans having healthier diets and Puerto Ricans and non-Hispanic Blacks having less healthy diets. Sedentary time was lower in Mexicans than in other groups in adjusted models. Examination of additional models, including home language, did not show significant differences in the estimates. Diet and activity behaviors varied across racial/ethnic subgroups. Specifically, Mexican children had healthier diets, the least amount of sedentary time, and the lowest rates of obesity among the Hispanic subgroups examined. Targeted interventions in ethnic subgroups may be warranted to address specific behaviors.
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